Empirical support for the high-density subset sum decision threshold

2015 ◽  
Author(s):  
T. E. O'Neil ◽  
T. Desell
Keyword(s):  
Empirical Support ◽  
High Density ◽  
Decision Threshold ◽  
Subset Sum

scholarly journals PKCHD: Towards A Probabilistic Knapsack Public-Key Cryptosystem with High Density

Information ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 75 ◽  
Author(s):  
Yuan Ping ◽  
Baocang Wang ◽  
Shengli Tian ◽  
Jingxian Zhou ◽  
Hui Ma
Keyword(s):  
Chinese Remainder Theorem ◽  
Success Probability ◽  
High Density ◽  
Public Key ◽  
Public Key Cryptosystem ◽  
The Public ◽  
Attack Model ◽  
Simultaneous Diophantine Approximation ◽  
Subset Sum ◽  
Linearization Attack

By introducing an easy knapsack-type problem, a probabilistic knapsack-type public key cryptosystem (PKCHD) is proposed. It uses a Chinese remainder theorem to disguise the easy knapsack sequence. Thence, to recover the trapdoor information, the implicit attacker has to solve at least two hard number-theoretic problems, namely integer factorization and simultaneous Diophantine approximation problems. In PKCHD, the encryption function is nonlinear about the message vector. Under the re-linearization attack model, PKCHD obtains a high density and is secure against the low-density subset sum attacks, and the success probability for an attacker to recover the message vector with a single call to a lattice oracle is negligible. The infeasibilities of other attacks on the proposed PKCHD are also investigated. Meanwhile, it can use the hardest knapsack vector as the public key if its density evaluates the hardness of a knapsack instance. Furthermore, PKCHD only performs quadratic bit operations which confirms the efficiency of encrypting a message and deciphering a given cipher-text.

An Extended Knapsack Public Key Cryptosystem

2013 ◽  
Vol 441 ◽  
pp. 678-681
Author(s):  
Xiao Ping Ji ◽  
Hai Bin Zhang ◽  
Bo Ying Wu ◽  
Guang Yu Li
Keyword(s):  
High Density ◽  
Public Key ◽  
Public Key Cryptosystem ◽  
Low Density ◽  
Subset Sum Problem ◽  
Encryption And Decryption ◽  
Subset Sum

We analyzed a typical cryptosystem and an easy extended knapsack subset sum problem is proposed. The solution is not chosen from any longer but from. Based on the problem, we construct a public key cryptosystem in which the plaintext is divided into some groups and each group has bits, so that the encryption and decryption can be very fast. The possible attacks are analyzed. Our cryptosystem not only can resist Shamir's attack but also can resist the low density attack, because of its high density. The number of the sequence is also much shorter than before with the same density.

Cryptanalysis of a hash function, and the modular subset sum problem

2019 ◽  
Vol 11 (1) ◽  
pp. 17-23
Author(s):  
Chris Monico
Keyword(s):  
Hash Function ◽  
High Density ◽  
Subset Sum Problem ◽  
Affine Maps ◽  
Subset Sum ◽  
Very High

AbstractRecently, Shpilrain and Sosnovski proposed a hash function based on composition of affine maps. In this paper, we show that this hash function with its proposed parameters is not weak collision resistant, for plaintexts of size at least 1.9MB (about {2^{24}} bits). Our approach is to reduce the preimage problem to a (very) high density instance of the Random Modular Subset Sum Problem, for which we give an algorithm capable of solving instances of the resulting size. Specifically, given plaintexts of about 1.9MB, we were able to produce other plaintexts of the same size with the same hash value in about 13 hours each, on average.

Trading Places, Trading Platforms: The Geography of Trade Policy Realignment

2021 ◽  
pp. 1-32
Author(s):  
Bryan Schonfeld
Keyword(s):  
Political Parties ◽  
Trade Policy ◽  
Free Trade ◽  
Electoral Systems ◽  
Empirical Support ◽  
High Density ◽  
Relative Positioning ◽  
Party Leaders ◽  
Advanced Economies ◽  
College Educated

Abstract What motivates politicians and political parties to shift their positioning on an issue? Focusing on the case of trade policy in countries with advanced economies and plurality electoral systems, I argue that the relative positioning of parties on an existing issue can change even when the preferences of the key actors (voters and politicians) are held constant, and even when party leaders continue to represent the same constituencies. In advanced plurality countries, college-educated voters support free trade, and high-density constituencies are predominantly represented by Left incumbents. As college-educated workers migrate to high-density constituencies in pursuit of higher wages, Left incumbents increasingly embrace free trade, while Right incumbents take more protectionist positions. I provide empirical support for several observable implications of my theory.

Planar defects in ordered (Ga,In)P

1988 ◽  
Vol 46 ◽  
pp. 902-903
Author(s):  
S. McKernan ◽  
C. B. Carter ◽  
D. Bour ◽  
J. R. Shealy
Keyword(s):  
Electron Diffraction ◽  
Vapor Phase ◽  
Growth Direction ◽  
High Density ◽  
Ordered Structure ◽  
Planar Defects ◽  
Diffraction Patterns ◽  
Ternary Semiconductors ◽  
Anion Species ◽  
Metallic Vapor

The growth of ternary III-V semiconductors by organo-metallic vapor phase epitaxy (OMVPE) is widely practiced. It has been generally assumed that the resulting structure is the same as that of the corresponding binary semiconductors, but with the two different cation or anion species randomly distributed on their appropriate sublattice sites. Recently several different ternary semiconductors including AlxGa1-xAs, Gaxln-1-xAs and Gaxln1-xP1-6 have been observed in ordered states. A common feature of these ordered compounds is that they contain a relatively high density of defects. This is evident in electron diffraction patterns from these materials where streaks, which are typically parallel to the growth direction, are associated with the extra reflections arising from the ordering. However, where the (Ga,ln)P epilayer is reasonably well ordered the streaking is extremely faint, and the intensity of the ordered spot at 1/2(111) is much greater than that at 1/2(111). In these cases it is possible to image relatively clearly many of the defects found in the ordered structure.

Quantitative defect studies in semiconductor TEM samples prepared by low angle ion milling

1995 ◽  
Vol 53 ◽  
pp. 512-513
Author(s):  
L. Mulestagno ◽  
J.C. Holzer ◽  
P. Fraundorf
Keyword(s):  
Sample Preparation ◽  
Milling Time ◽  
High Density ◽  
Low Density ◽  
Ion Milling ◽  
High Quality ◽  
Variable Angle ◽  
Major Disadvantage ◽  
Induced Defects

Due to the wealth of information, both analytical and structural that can be obtained from it TEM always has been a favorite tool for the analysis of process-induced defects in semiconductor wafers. The only major disadvantage has always been, that the volume under study in the TEM is relatively small, making it difficult to locate low density defects, and sample preparation is a somewhat lengthy procedure. This problem has been somewhat alleviated by the availability of efficient low angle milling.Using a PIPS® variable angle ion -mill, manufactured by Gatan, we have been consistently obtaining planar specimens with a high quality thin area in excess of 5 × 104 μm2 in about half an hour (milling time), which has made it possible to locate defects at lower densities, or, for defects of relatively high density, obtain information which is statistically more significant (table 1).

Using the scanning electron microscope for failure analysis of high density magnetic media

1987 ◽  
Vol 45 ◽  
pp. 392-393
Author(s):  
Evelyn R. Ackerman ◽  
Gary D. Burnett
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Failure Analysis ◽  
High Density ◽  
Magnetic Media ◽  
Specific Data ◽  
Retrieval Systems ◽  
Operating Environments ◽  
The Media ◽  
Scanning Electron

Advancements in state of the art high density Head/Disk retrieval systems has increased the demand for sophisticated failure analysis methods. From 1968 to 1974 the emphasis was on the number of tracks per inch. (TPI) ranging from 100 to 400 as summarized in Table 1. This emphasis shifted with the increase in densities to include the number of bits per inch (BPI). A bit is formed by magnetizing the Fe203 particles of the media in one direction and allowing magnetic heads to recognize specific data patterns. From 1977 to 1986 the tracks per inch increased from 470 to 1400 corresponding to an increase from 6300 to 10,800 bits per inch respectively. Due to the reduction in the bit and track sizes, build and operating environments of systems have become critical factors in media reliability.Using the Ferrofluid pattern developing technique, the scanning electron microscope can be a valuable diagnostic tool in the examination of failure sites on disks.

South Asian Stories: Firsthand Client Perspectives on Barriers to Accessing Speech-Language Pathology Services

2012 ◽  
Vol 19 (1) ◽  
pp. 29-36 ◽  
Author(s):  
Nidhi Mahendra
Keyword(s):  
South Asian ◽  
Empirical Support ◽  
Communication Disorders ◽  
Speech Language Pathology ◽  
Client Experiences ◽  
Individual Interviews ◽  
Timely Access ◽  
Phenomenological Perspective ◽  
Case Vignettes ◽  
Language Pathology

This article details the experience of two South Asian individuals with family members who had communication disorders. I provide information on intrinsic and extrinsic barriers reported by these clients in responses to a survey and during individual ethnographic interviews. These data are part of a larger study and provide empirical support of cultural and linguistic barriers that may impede timely access to and utilization of speech-language pathology (SLP) services. The purpose of this article is to shed light on barriers and facilitators that influence South Asian clients' access to SLP services. I provide and briefly analyze two case vignettes to provide readers a phenomenological perspective on client experiences. Data about barriers limiting access to SLP services were obtained via client surveys and individual interviews. These two clients' data were extracted from a larger study (Mahendra, Scullion, Hamerschlag, Cooper, & La, 2011) in which 52 racially/ethnically diverse clients participated. Survey items and interview questions were designed to elicit information about client experiences when accessing SLP services. Results reveal specific intrinsic and extrinsic barriers that affected two South Asian clients' access to SLP services and have important implications for all providers.

Sign in / Sign up

Export Citation Format

Share Document